Safety-valve.



PATENTED APR. 4, 1905.

F. SGHREID'I'. SAFETY VALVE.

APPLIOATION FILED` FEB. 24, 1903.

Wi fname:

vertical cylindrical extension a3.

Patented April 4, 1905.

YUNITED STATES PATENT OFFICE.

FRANK SOHREIDT, OF MANSFIELD, OHIO SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent N o. 786,317, dated April 4, 1905.

Application filed February 24, 1903. Serial No. 144,626.

To @ZZ whom it may concern:

Be it known that l, FRANK SCHREIDT, a citizen of the United States of America, and a resident of Mansfield, county of Richland, State of Ohio, have invented certain new and useful Improvements in Safety-Valves, of which the following is a specification.

The object of my invention is a safety relief -valve in which .the presence of packed joints is omitted and in which the rate of closing the main valve after it has been thrown from its seat may be regulated readily.

.ln the accompanying' drawings I have illustrated two forms of valve embodying' my invention.

Figure l is a central vertical sectional view of one form of my invention. Fig. 2 is a similar view of the other form of my invention. Fig. 3 is a detail sectional view of a slightlymodified form of the casing' of the main valve shown in Fig. 2.

Referring' to Fig. l, valve-casing` A has a downward interiorly-screw-threaded extension a, communicating with the live steam, and a lateral extension a', likewise interiorly screw-threaded to be connected to the exhaust. Upon top of the valve-chamber A a secondary chamber a2 is formed, above which is a Vithin casing A is a horizontal main valve B, which is beveled to lit seat formed upon the inner end of extension a. The other end of the valve-B projects into cap C, which ,is screwed into the casing A at a point opposite the outlet a. Between the cap O and valve B a coiled spring c is located. Valve B has a flange 5to fit against the inner walls of the casing, forming a chamber Z/ upon the side of the flange removed from the outlet. Chamber t communicates with the chamber a2 by means of a perforation a5 in the walls of casing A. Upon the side of extension a3 is a by-pass a, which communicates with the outlet a. lVithin extension a3 is a secondary valve D, which is seated downward against a valve seat al, formed in the wall between the chambers a2 and extension a3. Valve D is held to its seat by means of a'spring-pressed rod E, which extends upward through a cap F, which closes the upper end of extension a3 and upon which lE for raising the valve D when desired. Auxiliary valve D has near its lower end a horizontal flange cl, which contacts the inner walls of extension a3. ln the side wall of extension a3 and at a point below the ilange l when the auxiliary valve is seated is a perforation a, which leads into the by-pass a. Seated against the edges of the perforation is a plug H. The upper end of by-pass a communicates with the extension a3 by means of a perforation a. The operation of the device is as follows: Steam admitted at the inlet (L passes around flange into chambers and a2. lV hen the pressure of the steam exceeds the pressure at which the secondary valve D is set, the secondary valve is raised and the pressure in chamber a2 is released, thereby releasing pressure in chamber b', when the pressure upon the side of flange toward the valve-seat carries the valve B inward away from valve-seat di* and allows the excess of pressure to be relieved. The length of time auxiliary valve D will remain off its seat depends upon the situation of plug H relative to perforation as. The closer the relation between the perforation and the plug' the more slowly is the valve D returned to its seat, and consequently the longer the main valve B is held from its seat. By carrying plugH farther away from the perforation the closing of the valve D is made more rapid, and in consequence the main valve B returns to its seat more quickly.

Referring to Fig. 2, valve-casing A has reg'- istering with its outlet al a horizontal c vlindrical Walla, extending clear across the interior of the casing' and being closed from communication with the interiorthcreof except for a perforation am in its upper wall. Main Valve Bl is seated downward against this perforation a12 and has a horizontal liange 7)', fitting' against the inner wall of the casing A. Instead of the casing of the auxiliary valve D being formed integ'ral with the casing of the main. valve, as shown in Fig. 1, the casing M of the auxiliary valve is formed in a separate piece interiorly scre w-threaded to engage the upper end of casing A', upon the upper end of which is located a disk N, which forms the seat for auxiliary valve D and between which IOO the fiange L is formed and chamber al.

place of the by-pass communicating with the outlet, as in Fig. l, the by-pass in this modification has in its Walls a perforation M, placing' it in communication with the outer air.

The operation is as follows: Steam entering the inlet am passes up around the cylindrical Wall tu and around the main valve B', past the flange bf, and into eh amber com. When the pressure of the steam exceeds the pressure at which the auxiliary valve is set, it is raised from its seat, and the pressure in chamber al being released the main valve is carried upward by the pressure upon the lower side of fiange 72, the upper limit of travel of the valve being made by wings b coming in contact with disk N. In this modification, as in that aforedescribed, the length of time the auxiliary valve remains unseated depends upon the position of the plug H.

In the modification shown in Fig. 3 casing A2 of the main valve, instead of having alateral outlet, such as shown in Fig. 2, has an interior cylindrical extension am open upon both ends and communicating with a cupshaped outlet am. The auxiliary valve and its connections are all similar to that described, and shown in Fig. 2.

What I claim is l. In a safety-valve the combination of a valve-casing having an inlet and an outlet opening, a main valve upon the interior of the casing to control the outlet having' an annular fiange fitting against the walls of the casing and forming a chamber surrounding the valve adjacent to the valve-seat and a second chamber upon the end of the valve opposite to the end which contacts the seat, the annular flange contacting the Walls so as to allow the pressure of steam to pass around it into the second chamber, a secondary chamber having an enlarged perforation therein forming a valve-seat, an auxiliary valve exterior to the second chamber seated against said perforation and of' an area such as to be raised by the pressure of steam in the sccondary chamber when it exceeds a predetermined limit and a spring for holding the aux- In Y iliary valve to its seat until the pressure exceeds the predetermined pressure substantially as shown and described.

2. In a safety-valve, the combination of a valve-casing havingan inlet and an outlet, a main valve upon the interior of the casing to control the outlet, having an annular fiange fitting against the walls of the casing' and forming a chamber surrounding' the valve adjacent to the valve-seat, a second chamber upon the end of the valve opposite to the end which contacts the seat, the fiange contacting the Walls so as to allow the pressure of steam to pass around it into the second chamber, the second chamber having a perforation therein, an auxiliary valve exterior to the second chamber and seated against the perforation, the auxiliary valve having a fiange contacting' its walls and forming a chamber adjacent to its seat, the chamber having a perforation in its walls, a spring for holding the auxiliary valve to its seat, and a regulating-plug seated against the perforation, substantially as shown and described.

3. In a safety-valve the combination of a valvescasing having' an inlet and an outlet opening, the interior extension of the casing communicating with the outlet and closed from the inlet-opening', a perforation in the extension, a second casing fitting upon the upper end of the first casing. a valve-seat formed between the two casings, a main valve seated against the perforations in the extension and having a fiange contacting the walls of the main casing and forming a chamber with the valve-seat in the upper end of the easing, an auxiliary valve Within the second casing and contacting the seat formed between the two casings and having a flange forming a chamber' adjacent to the seat, the chamber having a perforation in its walls, and a regulating-plug seated against the perforation, substantially as shown and described.

FRANK SCIIREI DT. Iitnessesz F. H. BoGAnDUs, C. E. Sorrnurn'r. 

